<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }
    #canvas {
      background-color: gray;
    }
    body::after {
      content: '';
      display: block;
      position: absolute;
      top: 0;
      left: 200px;
      width: 1px;
      height: 400px;
      background-color: red;

    }
    body::before {
      content: '';
      display: block;
      position: absolute;
      width: 400px;
      height: 1px;
      background-color: red;
      left: 0;
      top: 200px;
    }
  </style>
</head>
<body>
  <canvas id="canvas" width="400" height="400"></canvas>
  <script src="../lib/index.js"></script>
  <script>
    const canvas = document.getElementById('canvas');
    const gl = canvas.getContext('webgl');

    const vertexShaderSource = `
      void main() {
        gl_Position = vec4(0.5, 0.5, 0.0, 1.0);
        gl_PointSize = 10.0;
      }
    `
    const fragmentShaderSource = `
      void main() {
        gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
      }
    `

    initShaders(gl, vertexShaderSource, fragmentShaderSource)
    gl.drawArrays(gl.POINTS, 0, 1)
    gl.drawArrays(gl.LINES, 0, 2)
    gl.drawArrays(gl.LINE_STRIP, 0, 3)
  </script>
</body>
</html>